What Your Kidney Lab Values Mean

A creatinine of 0.9 mg/dL is within the normal range for most adults — typically indicating normal kidney function.

Creatinine 1.1 mg/dL is normal for most adults — though it can already reflect mildly reduced function in a smaller or older person.

Creatinine 1.2 mg/dL sits at the upper end of normal — normal for a muscular man, but possibly reduced filtration for a woman or small-framed person.

Creatinine 1.3 mg/dL is borderline high for most adults — about one-quarter of kidney function can be lost before creatinine clearly rises.

Creatinine 1.4 mg/dL is above the normal range — kidney function is reduced, though the exact degree depends on age and muscle mass.

Creatinine 1.5 mg/dL represents clearly reduced kidney filtration in most adults — typically corresponding to eGFR 45-60 in a middle-aged person.

Creatinine 1.8 mg/dL indicates moderate kidney function reduction — roughly eGFR 35-45 in a typical adult. Specialist review is warranted.

Creatinine 2.0 mg/dL means kidney function is significantly reduced (eGFR roughly 30-40) — CKD stage G3b territory in most adults.

Creatinine 2.5 mg/dL represents severe reduction in filtration (eGFR roughly 20-30) — CKD stage G4 territory. Urgent evaluation is needed.

Creatinine 3.0 mg/dL means severe kidney failure — eGFR around 18-22. This is stage G4-G5 territory requiring specialist care.

Creatinine 4.0 mg/dL is kidney failure territory (eGFR roughly 12-15) — dialysis or transplant is usually required soon, if not already started.

eGFR 90 or above is normal kidney function. CKD is only diagnosed at this level if there are other damage markers (albuminuria, blood in urine, abnormal imaging).

eGFR 75 is normal for adults over 50 and only mildly reduced for younger adults. CKD requires a damage marker to be diagnosed in this range.

eGFR 60 is the diagnostic threshold for chronic kidney disease. Below 60 (sustained for 3+ months) = CKD; at 60 with damage markers = CKD.

eGFR 55 means mild-moderate reduction (stage G3a) — CKD if it persists 3+ months. This is the stage where kidney-protective treatment matters most.

eGFR 50 is stage G3a CKD — roughly half of kidney function is lost. Many people feel nothing at this stage; that's why testing matters.

eGFR 45 sits at the boundary between stages G3a and G3b. Below 45, risk of progression and heart disease rises significantly.

eGFR 40 is stage G3b — moderate-severe reduction. Progression risk is meaningful, and specialist monitoring is standard of care.

eGFR 35 means two-thirds of kidney function is gone (stage G3b). Specialist care is essential; medications and diet need active management.

eGFR 30 is stage G4 — severe reduction. Below this level, planning for renal replacement therapy becomes necessary.

eGFR 25 means kidney function is a quarter of normal. Symptoms of uremia may begin; dialysis preparation is actively underway.

eGFR 20 is severe CKD. Dialysis typically starts at eGFR 10-15 or earlier if symptoms/complications appear.

eGFR 15 is kidney failure — the threshold where dialysis is typically considered. Urgent specialist care is required.

eGFR 18 is severe (stage G4) CKD — approaching the kidney-failure range. Dialysis planning should already be underway.

BUN 22 is slightly above the typical upper limit of 20. Often harmless — but it can signal early dehydration or reduced kidney flow.

BUN 25 is elevated. The cause is usually prerenal (dehydration, low blood flow) when creatinine is normal — or kidney disease when creatinine is also high.

BUN 30 indicates significant azotemia — urea accumulation. With normal creatinine, it's usually prerenal; with high creatinine, it suggests intrinsic kidney disease.

BUN 40 reflects substantial urea accumulation. This needs evaluation — prerenal causes can be fixed with fluids, but intrinsic kidney disease must be excluded.

BUN 60 is severely elevated — significant azotemia requiring urgent evaluation. Uremic symptoms (nausea, confusion, itching) can appear in this range.

Potassium 3.2 is low (hypokalemia) — usually from losses rather than kidney disease. Levels below 3.0 need attention.

Potassium 3.4 is just below normal. Mild hypokalemia is common and usually easy to fix.

Potassium 3.5 is the lower limit of normal — acceptable, but trending toward hypokalemia.

Potassium 5.0 is at the upper edge of normal. In CKD, this is a warning level — the kidney's potassium handling is getting tighter.

Potassium 5.2 is mildly elevated (mild hyperkalemia) — common in CKD, especially with ACEi/ARB use. Not dangerous at this level but needs watching.

Potassium 5.5 is elevated hyperkalemia — the threshold where treatment is usually recommended, especially with ECG changes or CKD.

Potassium 5.8 is significantly elevated and carries heart-rhythm risk. This needs prompt medical attention.

Potassium 6.0 is critical hyperkalemia — significant risk of cardiac arrhythmia. This is a medical emergency.

Potassium 6.5 is dangerously high — arrhythmia risk is imminent. Emergency treatment is mandatory.

Potassium 7.0 is a life-threatening emergency — imminent risk of cardiac arrest from arrhythmia. This requires immediate emergency treatment.

Phosphorus 3.0 is within the normal range.

Phosphorus 4.5 is at the upper limit of normal — acceptable for now, but trending in the wrong direction in CKD.

Phosphorus 5.5 is above target for CKD patients (KDIGO target ~3.5-5.5 for dialysis; lower for earlier stages) — it begins to drive bone disease and vascular calcification.

Phosphorus 6.5 is significantly above target. Persistent elevation accelerates vascular calcification — the leading cause of death in dialysis patients.

Phosphorus 7.5 is dangerously high — significant calcification risk and possible itching, bone pain, and ectopic calcification.

Corrected calcium 8.0 is low (hypocalcemia). In CKD this usually reflects vitamin D deficiency and high phosphorus (secondary hyperparathyroidism).

Corrected calcium 8.5 is at the lower edge of normal — acceptable, but watch it in CKD.

Corrected calcium 10.3 is at the upper edge of normal. In dialysis, KDIGO advises avoiding hypercalcemia — this is a warning zone.

Corrected calcium 10.6 is hypercalcemia — needs evaluation for the cause and correction, especially in CKD/dialysis where it drives calcification.

Corrected calcium 11.5 is dangerously high — can cause confusion, kidney injury, and arrhythmias. Urgent treatment needed.

Sodium 130 is mild hyponatremia. Common and usually safe if gradual, but it signals a water-sodium imbalance worth understanding.

Sodium 128 is hyponatremia needing evaluation — the cause (fluid overload, diuretics, or water excess) determines whether to restrict fluid or adjust medications.

Sodium 135 is the lower edge of the normal range — a healthy result for most people, though it can reflect mild fluid excess in kidney disease.

Sodium 146 is mildly elevated — mild hypernatremia, usually from water loss rather than salt excess.

Sodium 150 is elevated hypernatremia — significant water deficit. Elderly patients and those who can't access water are most at risk.

Sodium 155 is severe hypernatremia — a large free-water deficit. Hospital evaluation is usually required.

UACR 15 mg/g is normal — no albuminuria.

UACR 45 mg/g is microalbuminuria (stage A2) — the earliest detectable kidney damage, most commonly from diabetes. This is the stage where treatment can prevent progression.

UACR 100 mg/g is established albuminuria — kidney damage is definite and progression risk is rising.

UACR 300 mg/g is the A3 threshold — severe albuminuria (macroalbuminuria). High risk of progression to kidney failure and cardiovascular events.

UACR 500 mg/g is heavy proteinuria — approaching nephrotic-range. The kidney is losing protein at a damaging rate.

UACR 700 mg/g is heavy albuminuria — far above the A3 threshold (300 mg/g) and approaching nephrotic range. High risk of progression and cardiovascular events.

UACR 1000 mg/g is nephrotic-range proteinuria — heavy losses causing edema, hyperlipidemia, and clotting risk. Specialist care is essential.

Hemoglobin 8.0 is severe anemia — in CKD this usually means advanced kidney failure with EPO deficiency. Transfusion may be needed in symptomatic cases.

Hemoglobin 7.5 is severe anemia — urgent evaluation. In CKD this reflects advanced EPO deficiency plus often iron deficiency, and transfusion is commonly needed for symptoms.

Hemoglobin 9.5 is moderate anemia — common in CKD stages 4-5. Below 10, treatment is typically indicated.

Hemoglobin 10.5 is within the KDOQI dialysis target range (10-11.5 g/dL) — the safe treatment window.

Hemoglobin 12.0 is normal for women and slightly low for men.

Hemoglobin 13.5 is normal for adults. In dialysis, values above 13 signal ESA overuse risk (TREAT trial: stroke risk above 13).

Bicarbonate 15 is severe metabolic acidosis — needs urgent evaluation and treatment.

Bicarbonate 18 is moderate acidosis — in CKD this level triggers treatment because acidosis accelerates kidney damage.

Bicarbonate 21 is just below normal — mild acidosis. In CKD, this is where treatment is recommended to protect kidney function.

Bicarbonate 26 is within the normal range.

Bicarbonate 30 is mildly elevated — often metabolic alkalosis or compensation for respiratory acidosis.

Uric acid 6.5 is at the upper limit for men — above the gout target (<6.0) if you have had attacks.

Uric acid 7.0 is above the typical upper limit — hyperuricemia that raises gout and uric-acid stone risk, and is very common in CKD.

Uric acid 8.0 is hyperuricemia — above the treatment target if gout has occurred; also a risk factor for kidney stones.

Uric acid 9.5 is high enough to cause gout attacks and uric-acid stones — treatment is usually indicated.

Uric acid 11.0 is severely elevated — high risk of gout, stones, and in acute settings, kidney injury (tumor lysis, crush injury).

Albumin 3.0 is low — reflects malnutrition, inflammation, or protein losses. In dialysis, this level is a red flag for poor outcomes.

Albumin 2.5 is significantly low — in CKD and dialysis it signals malnutrition, inflammation, or heavy protein loss, and is a strong predictor of poor outcomes.

Albumin 3.5 is at the lower edge of normal — acceptable, but worth protecting.

Albumin 4.0 is a healthy result — good nutritional status.

Albumin 4.5 is normal and reassuring — strong nutritional status.

Cystatin C 0.8 mg/L is within the normal range — consistent with normal or near-normal kidney function on the muscle-independent marker.

Cystatin C 1.1 mg/L is mildly elevated — suggesting eGFR around 60-75 by cystatin C. This is the range where cystatin C catches reductions that creatinine might miss.

Cystatin C 1.5 mg/L is clearly elevated — corresponding to eGFR roughly 40-50 by the CKD-EPI cystatin C equation. This confirms significant reduction when creatinine-based estimates were uncertain.

Cystatin C 2.0 mg/L is markedly elevated — corresponding to eGFR roughly 25-35, i.e., moderate-severe CKD by a muscle-independent measure.